Afghanistan is shaped roughly like a clenched fist
with the thumb extended out to the northeast. Afghanistan covers an area
of about 652,090 sq km (about 251,773 sq mi). Its maximum length from east
to west is about 1240 km (about 770 mi); from north to south it is about
1015 km (about 630 mi). The northwestern, western, and southern border
areas are primarily desert plains and rocky ranges, whereas the southeast
and northeast borders rise progressively higher into the major,
glacier-covered peaks of the Hindu Kush, an extension of the
western Himalayas. Only the northern border is formed by a river, the
Amu Darya.